In a deduplicated file system, which is often used on disk-based storage systems, i.e., hard disk drives (HDDs), namespace operations are generally expensive as accessing (e.g., reading) a directory may churn a system cache by way of write-erase cycles. A directory generally refers to a location for storing one or more files in a hierarchical file system.
For example, in a workload with a large directory (e.g., a directory having a significant amount of files, such as 100 or 1,000 files) or frequently accessed directory, accessing such directory may severely impact system performance as the number of write-erase cycles (churn) may increase for the system cache, thereby reducing the useful life span of the system cache.